1. Field of the Invention
This invention relates to a high-frequency semiconductor technique, and more particularly, to an automatic bonding tape or tape-like carrier (hereinafter referred to as "TAB tape") used to connect electrodes of a semiconductor device operating in a high frequency range, and circuit patterns formed on a ceramic or printed board on which such a semiconductor device is mounted.
2. Description of the Related Art
As conventionally known in the art of semiconductor technology, a TAB tape comprises an insulative flexible film made of, for example, a polyimide film strip having a number of longitudinal segments, each provided with a plurality of conductive metallic circuit patterns formed of, for example, copper foil, and electroplated with gold or the like.
As disclosed in U.S. Pat. No. 3,763,404, such a TAB tape is generally used in an automatic bonding process for connecting electrodes of semiconductor devices or chips to electrical circuits of a ceramic or printed board, via the conductive metallic patterns formed on the TAB tape.
Recently, semiconductor devices which can be used in a high-frequency range, of, for example, more than 10 GHz, are required for current high-technology information processes, and the conventional TAB tapes can no longer be used for such a high-frequency semiconductor device. This is because, if an ultra-high-frequency signal is received by the conductive patterns of the conventional TAB tape, a part of the high-frequency signal received by the conductive pattern would leak to an adjacent conductive pattern, to cause crosstalk, since a large number of conductive patterns are arranged with very small gaps therebetween.
Therefore, an improved TAB tape which can be used for a semiconductor device operating in an ultra-high-frequency range is urgently required.